Search Publications
Magnetic mirror structures observed by Cluster in the magnetosheath
Glassmeier, K. -H.; Treumann, R.; Constantinescu, O. D. +1 more
We present a method for identification of magnetic mirror structures (MMS) in multi-point spacecraft measurements and for deriving their full 3D geometry. Multiple minima in magnetic field data are no longer regarded as separate MMS but as belonging to the same mirror structure. The approach is based on fitting a model magnetic field to measured d…
The Nuclear Spectral Energy Distribution of NGC 6251: A BL Lacertae Object in the Center of an FR I Radio Galaxy
Chiaberge, Marco; Capetti, Alessandro; Gilli, Roberto +1 more
We determine the nuclear spectral energy distribution (SED) from the radio to the gamma-ray band for the FR I radio galaxy NGC 6251, by using data from the literature and analyzing Hubble Space Telescope and X-ray archival data. In the logν-log(νFν) representation, the SED has two broad peaks, and it is remarkably similar to those of bl…
A simple analytical expression for the power spectrum of cascading Alfvén waves in the solar wind
Laitinen, T.; Fichtner, H.; Vainio, R.
Alfvén wave transport in the solar wind, including non-linear spectral energy transfer, is studied. We present numerical solutions of wave transport using a diffusive flux function previously introduced for spectral energy transfer, and compare it with the analytical solution obtained for a convective flux function. The two models of cascading pro…
Optical and Near-Infrared Spectroscopy of a High-Redshift Hard X-Ray-emitting Spiral Galaxy
Graham, James R.; Eckart, Megan E.; Spinrad, Hyron +4 more
We present optical and near-infrared Keck spectroscopy of CXOHDFN J123635.6+621424 (HDFX 28), a hard X-ray source at a redshift of z=2.011 in the flanking fields of the Hubble Deep Field North (HDF-N). HDFX 28 is a red source (R-Ks=4.74) with extended steep-spectrum (α8.41.4 GHz>0.87 GHz) microjansky radio emiss…
The X-Ray Binary GRS 1741.9-2853 in Outburst and Quiescence
Muno, M. P.; Baganoff, F. K.; Arabadjis, J. S.
We report Chandra and XMM-Newton observations of the transient neutron star low-mass X-ray binary GRS 1741.9-2853. Chandra detected the source in outburst on 2000 October 26 at an X-ray luminosity of ~1036 ergs s-1 (2-8 keV; 8 kpc), and in quiescence on 2001 July 18 at ~1032 ergs s-1. The latter observat…
Plasma properties above coronal active regions inferred from SOHO/UVCS and radio spectrograph observations
Raymond, J. C.; Wu, R.; Kohl, J. +3 more
Information on coronal plasma was inferred from the joint analysis of type {II} radio bursts and SOHO UltraViolet Coronagraph Spectrometer (UVCS) observations. The data sample comprises 37 metric type {II} radio bursts observed by ground-based radio spectrographs in 1999, during the rising phase of the solar cycle. The coronal electron densities n…
The Multicolored Hot Interstellar Medium of ``the Antennae'' Galaxies (NGC 4038/4039)
Zezas, A.; Fabbiano, G.; Krauss, M. +2 more
We report the results of the analysis of the extended soft emission discovered in the Chandra ACIS pointing at the merging system NGC 4038/4039 (``the Antennae''). We present a multicolor X-ray image that suggests both extensive absorption by the dust in this system, peaking in the contact region, as well as variations in the temperature of differ…
Host Galaxies of Low-z Radio-loud Quasars: A Search of Hubble Space Telescope Archives
Treves, Aldo; Falomo, Renato; Pagani, Claudio
We searched the Hubble Space Telescope (HST) archives for unpublished Wide Field Planetary Camera 2 images of low-redshift (z<0.5) radio-loud quasars (RLQs). This led to the identification of 11 objects. Here we present the results of the analysis of these images from which we derive the properties of their host galaxies. All objects are clearl…
Hubble Space Telescope Imaging in the Chandra Deep Field-South. III. Quantitative Morphology of the 1 Million Second Chandra Counterparts and Comparison with the Field Population
Tozzi, P.; Hasinger, G.; Rosati, P. +8 more
We present quantitative morphological analyses of 37 Hubble Space Telescope (HST)/WFPC2 counterparts of X-ray sources in the 1 Ms Chandra Deep Field-South (CDFS). We investigate (1) one-dimensional surface brightness profiles via isophotal ellipse fitting; (2) two-dimensional, point-spread function-convolved, bulge+disk+nucleus profile fitting; (3…
Photometric Studies of the Triple Star ER Orionis
Kim, Ho-Il; Lee, Jae Woo; Kim, Chun-Hwey +2 more
A total of 1637 BVR CCD observations of the overcontact binary ER Ori are used as the basis for new light curves, including the first red one. From these measurements, new timings of minimum light have been calculated. The complex period variation can be sorted into a linear period improvement, a secular period increase of considerable magnitude, …